There are quite a few companies in Japan that offer forwarding services. They are all in the expensive side of things, and worth the $ only if what you want to buy only exists in Japan or if you can save enough money by buying from a dealer who only ships within Japan.

I made a spreadsheet when I tried to choose one. I make no claim on the accuracy of this information of the suitability of these companies for any purpose. Actually, I haven't even used their services, since I decided to buy directly from amazon.com.jp instead. I don't know if it was cheaper, but it probably was safer to skip the middle man. Do your own research, this information is probably out of date!